Recently, an electroluminescence element comprising an organic thin film (organic electroluminescence element) has been developed. For forming an organic thin film in an organic electroluminescence element, there are mentioned a vacuum evaporation method and a wet film formation method.
The vacuum evaporation method facilitates lamination, therefore having the advantages in that it improves charge injection from anode and/or cathode and facilitates exciton containment in light emission layer. The wet film formation method has the advantages in that it does not require a vacuum process and facilitates large-area film formation and facilitates incorporation of plural materials having different functions in one layer (coating liquid).
However, lamination is difficult in the wet film formation method, and therefore the method is inferior to the vacuum evaporation method in drive stability, and at present, it is not as yet on a practicable level except some cases. In particular, the wet film formation method may enable two-layer lamination using an organic solvent and a water-base solvent, but three-layer or more multi-layer lamination is difficult in the method.
To solve the problems with lamination, Patent Reference 1 has proposed a polymer compound having a crosslinking group and having repeating units (III-1) and (III-2) mentioned below, and discloses a lamination method in which the reaction of the crosslinking group makes the compound insoluble in organic solvent.

However, the polymer compound described in Patent Reference 1 has a crosslinking group at the 9-position of the fluorene ring thereof, and is therefore poor in electrochemical stability, especially in resistance to reduction (electron); and it is considered that the drive stability of the organic electroluminescence element comprising the polymer compound described in Patent Reference 1 may be insufficient.
Patent References 2 and 3 disclose polymer compounds each having a repeating unit represented by the formula mentioned below; however, in case where these compounds are used in producing devices, there occur some problems in that flat films could not be formed and the drive lifetime of the devices to be obtained is short.
